Two-dose Fostera® Gold PCV MH regimen yields performance advantages
Pigs in a study that received two doses of Fostera® Gold PCV MH, the new Zoetis vaccine for porcine circovirus type 2 (PCV2) and Mycoplasma hyopneumoniae (M. hyo), had numerically fewer reactions, less morbidity, less mortality and a $4.12 per pig advantage at marketing compared to a competitor’s vaccine.1
In a separate trial comparing one dose of the same two vaccines, Fostera Gold PCV MH performed as well as the competitor’s.2
Fostera Gold PCV MH is the only vaccine for PCV2 in the US to contain two genotypes — PCV2a and PCV2b — and in a challenge study, it protected against 2d,3 the leading PCV2 genotype in the US.4
Southeast ﬁeld trial
The two-dose ﬁeld trial was conducted on a farm in the Southeast, said Gene Nemechek, DVM, technical services, Zoetis. The overall health of the herd was good but PCV2d and M. hyo were in the environment, providing a natural challenge.
One group of 618 pigs received 1 ml of Fostera Gold PCV MH at 3 and 6 weeks of age. Another 623 pigs received the same protocol with Circumvent® PCV-M G2.
Throughout the trial, oral-ﬂuid and serology samples were tested for PCV and M. hyo by polymerase chain reaction (PCR), he said.
Before the trial, oral-ﬂuid sampling indicated no pigs were positive for PCV2. By mid-ﬁnisher stage, seven of nine oral-ﬂuid samples were PCV2-positive, but random serum sampling of individual pigs turned up zero of 16 as positive. Not surprisingly, sequencing of positive samples revealed the PCV2d strain. There were no positive M. hyo results based on oral-ﬂuid sampling throughout the trial, Nemechek said.
In the Fostera Gold PCV MH group, there were numerically fewer vaccine reactions, less morbidity and less mortality, and there were fewer culls at closeout — 0.49% in the Fostera Gold PCV MH group compared to 0.96% in the other group. In addition, 93.53% — 2.84% more — of pigs in the Fostera Gold PCV MH group went to the primary hog market compared to 90.69% in the Circumvent PCV-M G2 group, he said.
Growth and average daily gain were similar in both groups. However, net revenue provided by the producer demonstrated a $4.12-per-pig advantage for those in the Fostera Gold PCV MH group (Table 1), Nemechek reported.
The one-dose comparative trial was conducted on a farm in the Midwest and involved more than 2,600 pigs.5 It focused on morbidity, mortality and growth, said Noel Garbes, DVM, technical services, Zoetis.
At 3 weeks of age, pigs received one, 2 ml dose of either Fostera Gold PCV MH or Circumvent PCV-M G2.
Conducting a trial with this herd was challenging because there were multiple health issues, but the problems encountered were not unlike those often seen in the ﬁeld, Garbes said. There was inﬂuenza on the sow farm and, at the nursery, there were inﬂuenza and Streptococcus suis. Finishers developed Actobacillus suis 12 weeks after they were placed, causing eight pigs to die in 1 day, he said, and noted that treatment was administered as indicated.
Oral-ﬂuid and serology sampling was performed throughout the trial. The samples were tested for PCV2 with PCR, but to test for M. hyo, either PCR or ELISA was used.
There were a few samples positive for PCV2 and M. hyo at diﬀerent points throughout the study, but by the end of the trial at 19 weeks of age, no samples were positive for PCV2. In the Fostera Gold PCV MH group, two of 15 samples were positive for M. hyo by 19 weeks of age, and in the Circumvent PCV-M G2 group, one of 14 was positive and one of 14 was suspect, he said.
There were no signiﬁcant diﬀerences (p ≥ 0.05) in morbidity or mortality between the two vaccine groups nor in average daily gain (Table 2), Garbes said.
“In this study, one dose of Fostera Gold PCV MH performed similarly to Circumvent PCV-M G2 when administered at weaning,” he said.
Fostera Gold PCV MH has a duration of immunity (DOI) of at least 23 weeks for both PCV2 and M. hyo, so pigs are protected throughout the ﬁnishing stage. The DOI for Circumvent PCV-M G2 is at least 20 weeks (5 months) for only the PCV2 fraction of the vaccine.6 Other attributes of Fostera Gold PCV MH are safety and broader antigenic coverage, Garbes said.
“The safety of Fostera Gold PCV MH was demonstrated in the Southeast comparative trial and in a three-state safety study,”7 he said. Garbes attributes the vaccine’s safety to the adjuvant MetaStim®, which is “smooth.”
Research has demonstrated that because the vaccine has two PCV2 genotypes, it should provide the broadest antigenic coverage available against commonly circulating PCV2 genotypes as well as evolving PCV2 ﬁeld strains compared to a vaccine with only one genotype.8
The single, 2 ml dose of Fostera Gold PCV MH is indicated for pigs 3 weeks of age or older. The ﬂexible protocol given as two, 1 ml doses can be started as early as 3 days of age; however, Garbes and Nemechek prefer the two-dose regimen initiated at 3 weeks of age.
“With two doses,” Garbes explained, “all pigs are more likely to be vaccinated, whereas with one dose, some might be missed. Based on our work in the ﬁeld, we also think the immune response will be better if you wait until 3 weeks of age to start the vaccine protocol.”
All trademarks are the property of Zoetis Services LLC or a related company or a licensor unless otherwise noted. Circumvent is a registered trademark of Merck Animal Health.
1 Data on file, Study Report No. 17 PPTBIO-01-01, Zoetis LLC.
2 Data on file, Study Report No. 17 PPTBIO-01-02, Zoetis LLC.
3 Data on file, Study Report No. 16 PRGBIO-01-01, Zoetis LLC.
4 Opriessnig T, et al. A commercial porcine circovirus (PCV) type 2a-based vaccine reduces PCV2d viremia and shedding and prevents PCV2d transmission to naïve pigs under experimental conditions. Vaccine. 2017 Jan 5; 35(2):248-254.
5 Data on file, Study Report No. 17 PPTBIO-01-02, Zoetis LLC.
6 Circumvent PCV-M G2 label, Merck Animal Health.
7 Data on file, Study Report No. 16 PRGBIO-01-01, Zoetis LLC.
8 Data on file, Study Report Zoetis WO1, EpiCC PCV2 Analysis, Zoetis LLC.
DISCOVERIES, Issue 16
Discoveries is a series of research news reports written by the editors of Pig Health Today on behalf of the US Pork Business of Zoetis.
Posted on March 15, 2019